二氧化钛与碳纳米管协同作用的葡萄糖生物传感研究

Glucose biosensor based on the synergy between carbon nano-tubes and titanium oxide

在玻碳电极表面滴涂二氧化钛纳米颗粒-碳纳米管-壳聚糖(TiO2-MWNT-CS)复合物,待干后在其TiO2-MWNT-CS修饰电极表面电沉积一层均匀而致密的纳米铂(Pt),然后将葡萄糖氧化酶(GOD)固定于修饰电极表面,最后,为了防止酶的泄漏和干扰物质的干扰,将Nafion滴涂于修饰电极表面,制得新型的葡萄糖传感器。通过循环伏安法,交流阻抗技术和计时电流法考察了电极的电化学特性。在最佳的实验条件下,该传感器在3.0×10-6～1.45×10-3 mol/L范围内对葡萄糖有良好的线性响应,相关系数为0.9967(n=15),检测下限为9.5×10-7 mol/L(S/N=3)。由于纳米粒子间的协同作用,该传感器具有灵敏度高、稳定性和选择性好等优点。

A novel glucose biosensor has been presented in this paper. First, the TiO2-MWNT-CS composite was immobilized onto the surface of the glass carbon electrode（GCE）, then, a stable nano-Pt film was electrodeposited on the TiO2-MWNT-CS modified e- lectrode by applying an constant potential. Finally, glueose oxidase（GOD） and Nation were modified onto the film subsequently to fabrieate a glucose biosensor. The modified process and the electrochemical characteristics of the resuiting biosensor were character- ized by cyclic voltammetry（ CV）, electrochemical impedance spectroscopy（ EIS）, and chrpnoamperometry. Under the optimal condi- tions, a linear dependence of the catalytic current upon glucose concentration was obtained in the range of 3.0x10-6 tol. 45x 10-3 mol/L with a detection limit of 9.5x 10-7 mol/L（ S/N= 3 ）. In addition, the biosensor showed high sensitivity, good stability and ex- cellent selectivity